“I think certainly there’s a strong circumstantial case now, especially the link between the decoded messages and Rackstraw,” he said.

Observers have said Rackstraw had the training and the motive to pull off the heist. He left the Army months before the hijacking. Edwards reached Rackstraw by phone. He declined to answer questions, telling Edwards he would only speak face-to-face.

“How confident are you that D.B. Cooper is Robert Rackstraw?” Edwards asks Sherwood.

“If I were him, I’d be extremely nervous,” Sherwood said.

A FBI spokeswoman said the agency is no longer actively investigating the case, and declined to confirm if Rackstraw was ever a suspect.

“The FBI has received an immense number of tips provided by members of the public, but none to date have resulted in a definitive identification of the hijacker,” she said in a statement. “The tips have conveyed plausible theories, descriptive information about individuals potentially matching the hijacker, and anecdotes — to include accounts of sudden, unexplained wealth. In order to solve a case, the FBI must prove culpability beyond a reasonable doubt, and, unfortunately, none of the well-meaning tips or applications of new investigative technology have yielded the necessary proof.”